Paul A Bedrosian
Science and Products
Extreme‐value geoelectric amplitude and polarization across the northeast United States
Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey,...
Love, Jeffrey J.; Lucas, Greg M.; Bedrosian, Paul A.; Kelbert, Anna Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with...
Love, Jeffrey J.; Lucas, Greg M.; Kelbert, Anna; Bedrosian, Paul A.
On the feasibility of real-time mapping of the geoelectric field across North America
A review is given of the present feasibility for accurately mapping geoelectric fields across North America in near-realtime by modeling geomagnetic monitoring and magnetotelluric survey data. Should this capability be successfully developed, it could inform utility companies of magnetic-storm interference on electric-power-grid systems. That real...
Love, Jeffrey J.; Rigler, E. Joshua; Kelbert, Anna; Finn, Carol A.; Bedrosian, Paul A.; Balch, Christopher C. Geoelectric hazard maps for the Mid-Atlantic United States: 100 year extreme values and the 1989 magnetic storm
Maps of extreme value geoelectric field amplitude are constructed for the Mid‐Atlantic United States, a region with high population density and critically important power grid infrastructure. Geoelectric field time series for the years 1983–2014 are estimated by convolving Earth surface impedances obtained from 61 magnetotelluric survey sites...
Love, Jeffrey J.; Lucas, Greg M.; Kelbert, Anna; Bedrosian, Paul A. Extreme-event geoelectric hazard maps: Chapter 9
Maps of geoelectric amplitude covering about half the continental United States are presented that will be exceeded, on average, once per century in response to an extreme-intensity geomagnetic disturbance. These maps are constructed using an empirical parameterization of induction: convolving latitude-dependent statistical maps of extreme-value...
Love, Jeffrey J.; Bedrosian, Paul A. Water-resources and land-surface deformation evaluation studies at Fort Irwin National Training Center, Mojave Desert, California
The U.S. Army Fort Irwin National Training Center (NTC), in the Mojave Desert, obtains all of its potable water supply from three groundwater basins (Irwin, Langford, and Bicycle) within the NTC boundaries (fig. 1; California Department of Water Resources, 2003). Because of increasing water demands at the NTC, the U.S. Geological Survey (USGS), in...
Densmore, Jill; Dishart, Justine E.; Miller, David M.; Buesch, David C.; Ball, Lyndsay B.; Bedrosian, Paul A.; Woolfenden, Linda R.; Cromwell, Geoffrey; Burgess, Matthew K.; Nawikas, Joseph; O'Leary, David; Kjos, Adam; Sneed, Michelle; Brandt, Justin T. Geoelectric monitoring at the Boulder magnetic observatory
Despite its importance to a range of applied and fundamental studies, and obvious parallels to a robust network of magnetic-field observatories, long-term geoelectric field monitoring is rarely performed. The installation of a new geoelectric monitoring system at the Boulder magnetic observatory of the US Geological Survey is summarized. Data from...
Blum, Cletus; White, Tim; Sauter, Edward A.; Stewart, Duff; Bedrosian, Paul A.; Love, Jeffrey J. Hydrogeophysical investigations of earthen dams – Two California case studies
Excessive groundwater seepage can be a common engineering concern with earthen dams. The application of geophysical methods, whether for characterization or for long-term monitoring, to help inform mitigation strategies is becoming a more common addition to these investigations. The U.S. Geological Survey (USGS) has completed geophysical...
Burton, Bethany L.; Bedrosian, Paul A.; Minsley, Burke J.; Ikard, Scott; Powers, Michael H. Down to Earth with an electric hazard from space
In reaching across traditional disciplinary boundaries, solid-Earth geophysicists and space physicists are forging new collaborations to map magnetic-storm hazards for electric-power grids. Future progress in evaluation storm time geoelectric hazards will come primarily through monitoring, surveys, and modeling of related data.
Love, Jeffrey J.; Bedrosian, Paul A.; Schultz, Adam Geoelectric hazard maps for the continental United States
In support of a multiagency project for assessing induction hazards, we present maps of extreme-value geoelectric amplitudes over about half of the continental United States. These maps are constructed using a parameterization of induction: estimates of Earth surface impedance, obtained at discrete geographic sites from magnetotelluric survey data...
Love, Jeffrey J.; Pulkkinen, Antti; Bedrosian, Paul A.; Jonas, Seth ; Kelbert, Anna; Rigler, Erin (Josh); Finn, Carol A.; Balch, Christopher; Rutledge, Robert; Waggel, Richard; Sabata, Andrew; Kozyra, Janet; Black, Carrie Making it and breaking it in the Midwest: Continental assembly and rifting from modeling of EarthScope magnetotelluric data
A three-dimensional lithospheric-scale resistivity model of the North American mid-continent has been estimated based upon EarthScope magnetotelluric data. Details of the resistivity model are discussed in relation to lithospheric sutures, defined primarily from aeromagnetic and geochronologic data, which record the southward growth of the...
Bedrosian, Paul A. A comparison of helicopter-borne electromagnetic systems for hydrogeologic studies
The increased application of airborne electromagnetic surveys to hydrogeological studies is driving a demand for data that can consistently be inverted for accurate subsurface resistivity structure from the near surface to depths of several hundred metres. We present an evaluation of three commercial airborne electromagnetic systems over two test...
Bedrosian, Paul A.; Schamper, Cyril; Auken, Esben
Scientists Discover New Clues to Mount St. Helens Unusual Location
The atypical location of Mount St. Helens may be due to geologic structures that control where deep magmas can rise through the crust, as suggested by new findings published today in Nature Geoscience.